To the op. In case you aren't aware. It has been kind of implied in the topic by baldy110 that you don't have to get a Kawasaki master cylinder. Honda, Suzuki, Ducati, etc can be used. be aware that some modern mc's don't have a mirror orifice & some are for 1" handlebars (
probably most metric cruisers have 1" bars).
For the modern brake light switch: if you don't want to cut & splice the old brake light switch or make your own wire lead, the brake switch wire lead from a KZ1000P police can be used & it will probably be a direct swap with the old brake light switch. only problem is that the wires don't get listed very often on EB & new is kind of pricey, about $20.